Exemplary embodiments pertain to the art of detecting damper resistor degradation and/or failures.
Power filters can be used on, for example, motor controllers and power converters to reduce current and voltage harmonics as well as for electromagnetic compatibility (EMC) compliance. A basic building block of a power filter is a low pass filter comprised of an inductor L and a capacitor C. This filter typically also contains a damper circuit comprised of a capacitor and a damper resistor R.
Damper resistors are used for helping meet harmonic current draw requirements from standard AC busses. However, degradation or loss of a damper resistor can result in degradation of system performance in the form of increased dissipation losses input feeders. Additionally, the degradation or loss of a damper resistor can increase voltage stresses in other users of a standard bus that is affected by the damper resistor. Further, the failure or degradation of damper resistors can result in a latent failure that is not detectable by most testing at the product level or by Line-replaceable unit (LRU) sense protection functions while it is operating in the field.
Accordingly, there is a desire to provide a system and/or method for detecting degradation and/or loss of a damper resistor.